White aluminum oxide is made from alumina, which is a highly refined and oxidized product that is derived from the ore of aluminum. This alumina is then fused in high temperature furnaces, where it becomes the aluminum oxide abrasive. The bright white color of this product is a sign of its purity - it is almost 100% pure. One advantage that the white has over the brown is that the surface of the particle is sharper, so it will have better cutting action. The particle size is 60 micron. Packed in a 50 pound box.